Rocker arm for an engine

Abstract

A rocker arm is adapted for use with an engine including a push rod, a valve unit and a pivot ball disposed on a supporting frame. The rocker arm is connected pivotally to the supporting frame, and includes a main plate having a central opening defined by an upper edge, a horizontal lower edge disposed under the upper edge, and two curved lateral edges interconnecting the upper and lower edges. The lower edge has an intermediate portion formed with an outwardly flared recess that defines an upwardly facing socket engaging the pivot ball. A first arm plate is connected integrally to a lateral side of the main plate and is driven by the push rod. A second arm plate is connected integrally to an opposite lateral side of the main plate and operates the valve unit.

1. A rocker arm for an engine, the engine including a supporting frame, a push rod, a valve unit and a pivot ball disposed on the supporting frame, said rocker arm being adapted to be connected pivotally to the supporting frame and being adapted to be driven by the push rod to operate the valve unit, said rocker arm comprising:
 a main plate having opposite lateral sides and formed with a central opening defined by an upper edge, a horizontal lower edge disposed under said upper edge, and two curved lateral edges interconnecting said upper and lower edges, each of said lateral edges of said opening is outwardly concaved, said lower edge having an intermediate portion formed with and outwardly flared recess that defines an upwardly facing socket adapted to engage the pivot ball; 
 a first arm plate connected integrally to one of said lateral sides of said main plate and adapted to be driven by the push rod; and 
 a second arm plate connected integrally to the other one of said lateral sides of said main plate and adapted to operate the valve unit, 
 wherein said lateral edges of said opening are adjacent respectively to said first and second arm plates, one of said lateral edges of said opening adjacent to said second arm plate having a curvature radius smaller than that of the other one of said lateral edges of said opening adjacent to said first arm plate.